Multicomponent interpolymers of vinylidene cyanide



United States Patent MULTICOIVIPONENT INTERPOLYMERS OF VINYLIDENE CYANIDE Harry Gilbert, Cuyahoga FaHs, and Floyd F. Miller, Wadsworth, Ohio, assignors to The B. F. Goodrich Company, New York, N. Y., a corporation of New York No Drawing. Application January 26, 1952, Serial No. 268,461

13 Claims. (Cl. 26078.5)

This invention relates to novel multicomponent poly mers and methods for the preparation thereof, and pertains more particularly to interpolymers of vinylidene cyanide with two or more conjugated aliphatic dienes, which interpolymers are extremely valuable synthetic resins, being especially useful in the preparation of filaments, films and the like.

Monomeric vinylidene cyanide is a clear liquid at room temperature and a crystalline solid at 0 C. It melts in the range of 6.0" C. to 9.7 C. depending on purity, with purest samples melting at 9.0 C. to 9.7 C., and it boils at 40 C. at a reduced pressure of mm. of mercury. The monomer is quite sensitive to Water, undergoing on contact therewith at room temperature an instantaneous homopolymerization reaction to give a solid, water insoluble resin. Methods for the preparation of monomeric vinylidene cyanide are disclosed in U. S. Patents 2,476,270, 2,502,412 and 2,514,387.

In copending applications, Serial Nos. 159,146 and 159,147, filed April 29, 1950, it is disclosed that monomeric vinylidene cyanide possessing the above properties polymerizes readily with aliphatic conjugated dienes to give hard, horny, resinous, non-rubbery two component copolymers. Such copolymers are further unique in that they are essentially 1:1 alternating copolymers, that is, copolymers possessing the structure:

M1MaM1M2hM1-M2 wherein each M1 is a vinylidene cyanide unit HON each M2 is a unit of an aliphatic conjugated diene, and x is a polydigit number. The fact that the copolymers thus obtained are essentially 1:1 alternating copolymers is determined by nitrogen analysis of the copolymer which shows that the two monomers enter the polymer chain in essentially equimolar ratios regardless of the degree of monomer to polymer conversion and of charging ratio. Further supporting evidence for this fact is found in the copolymerization equation of F. M. Lewis, C. Walling et al., Journal of the American Chemical Society, volume 70, page 1519 (1948):

wherein:

M1=concentration of unreacted monomer M1 M2=concentration of unreacted monomer M2 r1=ratio of the rate constants for the reaction of an M1 type radical with M1 and M2 respectively rz=ratio of the rate constant for the reaction of an M2 type radical with M2 and M1 respectively 2,716,104 Eatented Aug. 23, 1955 When the product of n and r2 (values of r1 and r2 being determined by solving the equation for r1 and rz) is equivalent to 0, a 1:1 alternating copolymer is formed, that is, a copolymer having the structure shown hereinabove. It has been found that the product of n and r2 as calculated for two component copolymers of vinylidene cyanide with aliphatic conju: gated dienes is substantially 0, so that the equation clearly indicates that an essentially 1:1 alternating copolymer is formed.

However, while useful filaments, films and other shaped articles can be prepared from copolymers of vinylidene cyanide with aliphatic conjugated dienes, said copolymers possess several undesirable properties. For example, two component copolymers of vinylidene cyanide with dienes generally are very high melting and have a relatively short melt life, so that difiiculty is encountered in fabricating such copolymers into filaments, films and the like. Also, such copolymers are insoluble in most solvents ordinarily utilized 1n preparing polymer solutions.

Accordingly, it is an object of the present invention to modify the properties obtained in two component copolymers of vinylidene cyanide and dienes so that the resulting materials may be easily fabricated into filaments, films and other shaped articles.

Another object of this invention is to provide interpolymers containing vinylidene cyanide and at least two aliphatic conjugated dienes, which interpolymers can be readily melt spun, cast or molded.

It is another object of this invention to polymerize vinylidene cyanide with two or more aliphatic conjugated dienes to give interpolymers which possess a lower melting point and a longer melt life than do two component copolymers of vinylidene cyanide with conjugated aliphatic dienes.

It is still another object of this invention to polymerize vinylidene cyanide with two or more aliphatic conjugated dienes in order to obtain interpolymers which are soluble in common solvents. Other objects will be apparent from the description which follows.

It has now been discovered that the above and other objects are readily accomplished by polymerizing vinylidene cyanide with at least two aliphatic conjugated dienes. Interpolyrners obtained in this manner possess lower melting points and longer melt life than two component copolymers of vinylidene cyanide with dienes and additionally are soluble in a large number of solvents commonly utilized with polymeric materials. Accordingly, such interpolymers are extremely valuable materials in that they can be either melt or solvent spun into filaments which possess many useful properties, including high tensile strength and resistance to the action of alkalis, acids and the weather.

Among the conjugated aliphatic dienes which may be polymerized with vinylidene cyanide to form the interpolymers of this invention are included for example, butadiene-1,3, 2-methyl butadiene-1,3, piperylene, 2,3- dirnethyl butadiene-1,3, 1,2-dimethyl butadiene-1,3, 1,3- dimethyl butadiene-1,3, l-ethyl butadiene-1,3, 1,4-dimethyl butadiene 1,3, 2 neopentyl butadiene 1,3, 2 methyl pentadiene 1,3, 1 phenyl butadiene 1,3, 2-chloro-butadiene-1,3, 2-bromo-butadiene-l,3, 2-iodobutadiene-1,3, 2-chloro-3-methyl butadiene-1,3, l-bromo- 2-methyl butadiene-1,3, 1-bromo-2-methyl butadiene-1,3, 2-iodo-3-methyl butadiene-1,3, 1-fiuoro-2-methyl butadiene-1,3, 3-fluoro-butadiene-1,3, 3-bromo-butadiene-1,3, and the like. It is to be understood, of course, that the above compounds represent but a few of the dienes which may be employed in preparing the polymeric materials of.this.invention, .for any of the generic class of conjugated aliphatic dienes may be utilized with good results. While the vinylidene cyanide is always present in the polymer in substantially 5 0 mole per cent regardless-of the quantity of vinylideneicyanide monomer 'chargedoriginally,the'respective quantities of the dienes Which;entcr into the polymer chain may be varied widely while still .obtaining interpolymers Whichpossess useful properties not possessed by two component copolymers of vinylidene cyanide with thedienes. For example, interpolymers containingaslittle'as 2 mole per cent-or-as much as 45- mole percent 'ofone'of the diene components possess'softening points markedly lower than two component copolymers of vinyl-i'dene 'cyanide'with dienes and additionally are. more soluble in common solvents than are said-copolymers. The quantity of the dienecomponents -=in the'polymer chain"canbe"accurately controlledsimplyby varying the 'chargingrati'ocf' the diene" monomers. Accordingly, .the amount'of'any'dieneentering the polymer chain can be increasedbyincreasi-ng the quantity of that monomer in the polymerization charge. To illustrate, the specific examples'hereinbelowshow that-one of the dienes may be chargedinana-mount as small as llllmole percent or as highas l .1*mole=per cent for each mole per cent'of vinylidene' cyanide. Moreover, "both the vinylidene cyanide and the dienes may be charged in amounts other than tlrose'shown-the specific examples and thezinterpolymers obtainedwill difier in'propertiesfrom two component copo'lymers 'of'vinylidene cyanide-with the dienes.

"It is*"disclosed in the-'copendingapplications-referred to hereinabove that vinylidene-cyanide reacts quite readily with conjugated dienes to form a Diels-Alder type adduct and'that thisweactionicompetes strongly with the polymerization of vinylidene cyanide with the vdienes. It is also disclosed in said coperiding applications that vinylideneeyanide polymerizes -ionic-allyin-thepresence of a *number'of substances suchas water, alcohols, esters, ketones'and the 'liketmtorm a homepolymerwlhichis of -1ow=molecular weight (below 25,000)..and of little practical value. Accordingly, in' preparing the inter-polymers. of the present invention care must be taken to prevent' ntirely or reduce tea-minimum the two competing-side reactions. This is besraccomplished by carrying out the polymerization in' a single phase system i and in the presenceof a veryactive free radicalpolymerization catalyst. In this manner both the-tendency for-adduct formation: and: for *ionic =homepolymerization 'of the vinylidene cyanide to occur are greatly 'repressed and high conversions ofrmono- 'mer to polymer are secured.

"akpreferred method of carrying; out thepolymerization consistsin first-dissolving the monomersina liquid arornatic hydrocarbon such as'benzene and halogenated: ben- "zenes; which are especially preferred, -toluene,'methyl toluene, "or the like, I desirably in an amount such. that the solventcomprises'50 to-80% or moreby-Weight of: the totaksblution. -A 'free radical" polymerization catalyst is added to thesolution =and the resultingmixture heated: to =a temperature of'from -'15C. .to 100 C.,.preferably at 0? C. to 40 C., whereuponpolymerizationioccurs to form thedesired interpolymer as awhite .powder of small "particle size, i thepolymerization requiring approximately 1 1 m- 24 hoursin' most instances. "formed maybeseparated fromthepolymerizationmedium simply by -filtering,-' or= if desired: the r polymerization: medium can be separated from the polymer and'recoveredzby "distillation."

EA second'metho'd-ofi polymerization, -less"desirable than "the-above" method, but whichmay'be' successfully utilized, consists in" agitating the monomers "in aliquid aliphatic hydrocarbon (in'which vinylidene cyanide "monomer -is only very slightly soluble), for.exan 1ple,hexane' or heptane, and heating in the presence of a'free radicalpoly- .ime'rization catalyst whereupon the interpolymer forms and .zmaybe separated. from. the polymeiiza'tionmedium by filtering or by other conventional separation means.

The polymerization may also be carried out on a continuous basis simply by adding, continuously or intermit tently, resh quantities of the monomers, and also of catalyst and solvent or diluent, if desired, to the polymeriza- & tion mixture during the course-bf: the polymerization.

1 organic mercaptan as disclosed in a copending application,

Serial No. 346,04l, filedIMarch 31, 1953, or the combination of an inorganic acid with an organic thiol (mercaptan) such .as methanethiol, l-butanethiol, toluenethiol and the like, the latter catalyst combination beingdisclosed 2' in another copendingapplication, Serial No. 346,042, .filed March 31, 1953. The combination of sulfur. dioxide with ahydroperoxide is also. a useful catalyst in the preparation of. interpolymers of vinylidene cyanide.

Another class of catalysts useful in; preparing inter-polymers according tothis invention comprises compounds of they structure wherein each R is a hydrocarbon radical. Examples 'of compounds of-this 'class include alpha,alpha.-azodiisobutyronitrile, alpha,alpha'.-azobis (alpha,beta-:dimethylbutyronitrile), .alpha,alpha-azobis (alpha-cyclopropionitrile), and the like. Theuseof this type ofcatalyst in preparing-polymers of vinylidene-cyanide isdisclosed in copending application, Serial-No. 288562, filed May 17,

1952. Diazo'compoundsiother than those which possess thezabovestructure:are not useful in-theppolymerization process as they initiate the-ionic homopolymerizationxof the vinylidene ".cyanidermonomer to the *extentzrthatnone of .ther desired interpolyrner is obtained.

Other catalysts which .are -.usefu1- in: thepolymerization include the peroxygen compounds such as silver peroxide,

the perborates,athe-zpercarbonates,.benzoyhperoxide, ca-

The interpolymer thus proyl peroxide, lauroyl peroxide, acetone peroxide, acetyl benzoyl peroxide, 'cumene-hydroperoxide, :o,o-dichlorobenzoyl peroxide, o,o'-dibromobenzoyl peroxide, caprylyl peroxide, pelargonyl peroxide ..te1tiary butyl hydroperoxide, tetralin peroxide, and the like.

The amount of catalyst utilized is not critical and may be varied widely. In general, however, from 0.01 to 5% 'by weight (based on the total weight of "monomers charged)- of the catalyst 'is utilized.

The' following examples illustrate more fully .the preparation of interpolymers of vinylidene cyanide :with: two or more conjugated aliphatic 'dienes. I-The examples are not, however, to be construed as a limitation ;upon 5 the i 'scope of the invention;forthereare,'ofzcourse,mumerous EXAMPLES I-TO VI A series of tripolymersisgprepared by dissolving varying quantities of vinylidene. cyanide, butadiene-1,3 and Z-methyl butadiene-1,3 in benzene, adding a mixture of thiophenol and sulfur dioxide in benzene as a polymeriza- 3 tion catalyst, zandymaintainingthe resulting-.mixture .at

0 C. for =.eighteen-.hours,.:a the end: of.which1 time the vinylidene cyanide charged;:isn'substantially all converted to polymer. "The-monomer chargingzr'atios; quantities of "catalyst'usedymonomer'to polymer conversiomand;sof-ten- 75 ing point of the polymer are reeorded-in 'l able It below.

Table I Example I II III IV V VI Mole percent Vinylidene Cyanide Charged 45 45 45 45 45 45 Mole percent Butadiene-1,3 Charged. 0 15 25 35 45 50 Mole percent 2-Methyl Butadiene-1,3

Charged 55 40 30 20 5 Parts Thiophenol Charged 0. 137 0. 137 0. 137 0. 137 0. 137 0. 137 Parts S0: Charged 0. 2 0.2 0. 2 0. 2 0.2 0. 2 Conversion (Based on Vmyhdene Cyanide Charged) 87 88. 5 94 94.5 98 97 Melting Point of Polymer 185 195 220 241 256 262 EXAMPLES XIII TO XVII Tripolymers of vinylidene cyanide, butadiene-1,3 and methyl pentadiene-1,3 (a mixture of Z-methyl and 4- methyl pentadiene-l,3; density=0.7l6) areprepared in All of the tripolymers thus obtained possess very sharp melting points and are crystalline materials. A two component copolymer of vinylidene cyanide with butadicue-1,3 melts at 270 C. It will be noted, therefore, that as the quantity of the third monomer, 2-methyl butadione-1,3, is increased, the softening point of the resulting tripolymer is proportionately decreased, so that by varying the monomer charging ratios it is possible to obtain a tripolymer having any desired softening point.

benzene solution utilizing a mixture of 0.10 part of cumene hydroperoxide and approximately 0.07 part of hydrochloric acid in benzene as the polymerization catalyst:

0.09 part of p-thiocresol is added as a chain transfer agent and the polymerization mixture is maintained at 0 C. for 24 hours. The monomer charging ratios, polymer melt EXAMPLES VH1 TO XII points and other pertinent data are recorded in Table III Tripolymers of vinylidene cyanide, butadieue-l,3 and 25 below.

EXAMPLES XVIII TO XXI Tripolymers of vinylidene cyanide, butadiene-l,3 and piperylene (a mixture of the cis and trans forms) are prepared in benzene solution utilizing a mixture of hydro- Chloric 6111116116 hydropflroxide and Sulfur dioxide as 2,3-dimethyl butadiene-L3 are prepared according to the the Polymerization catalyst, the temperature being mainmethod of Examples XIII to XVII. The pertinent data tained at 20 C. for 25 hours. Thiocresol is added as a are recorded in Table IV below:

The pertinent data are recorded Also, when the above examples are repeated substituting other of the dienes disclosed hereinabove for those of chain transfer agent. in Table II below.

Table II Example VII VIII IX X XI XII le ercent Vin lidene C ide flhargedn -3?" 45 45 45 45 45 B t diene-l 3 li rg ffi fun n? 1 o 2g s 52 I ent Pi e lene Char ed 55 %a r ss l lfiocresol ii 0. 13 0. 13 0. 13 0. 13 0. 13 1 0. 13 Parts Cumene flydroperoztglfl fl 0. 1 0. 1 0. 1 0. 1 0. 1; 0. 1

S lution 1n l iz r yf 2 1 3 5 3. 5 3. 5 3.5 3. 5- 3. 5

Solution .48 SO in l e nz e 2 1.0 1.0 1.0 1.0 1.0 1.0 Melting Point of Polymer, 210 250 260 the examples, interpolymers are obtained which are substantially equivalent to those of the specific examples.

From the foregoing description of the invention it will be seen that the interpolymers of the present invention 7 constitute a new and useful class of polymeric materials.

From the above data it can again be seen that as the quantity of the third monomer, piperylene in this instance, is increased, the melting point of the polymer is decreased, this property again affording a convenient means for tailoring the polymer to suit any particular need.

7 t It is apparent, therefore, that various embodiments of the invention, in addition to those disclosed, may be provided without departing from the spirit and scope of the inven- 7 tion as defined in the appended claims.

We claim: 1. An interpolymer comprising vinylidene cyanide copolymerized with two conjugated aliphatic dienes, the t vinylidene cyanide component being derived from monomeric vinylidene cyanide which is a crystalline solid at 0 C., havinga melting point when in purest form of It substantially 9.0 C. to 9.7 C., and being character'- ized chemically by the ability to undergo on contact with water at room temperature an instantaneous h0- mopolymerization reaction to give a solid water-insoluble resin, said zinterpolymer containing substantially 50 mole per cent. copolymerized vinylidene cyanide.

2.;Aninterpolymer comprising vinylidene cyanide copolymerized with two conjugated aliphatic dienes, one of which is:butadiene-1,3, the'vinylidene cyanide component beingderived from monomeric vinylidene cya- 5 and methyl 'pentadiene, the vinylidene cyanide compo- U nent being derived from monomeric vinylidene cyanide which is a crystalline solid at 0 C., having a melting point when in purest form of substantially 9.0 C. to 9.7 C., and being characterized chemically by the ability to undergo on contact'with water at'room temperature an instantaneous homoploymerization reaction'to give a solid Water-insoluble resin, said inter-polymer containing substantially 50 mole per cent copolymerized vinylidene cyanide.

4. A tripolymer of vinylidene cyanide, butadiene-l,3

actionto givea solid water-insoluble resin, said inter polymer containing substantially 50 mole per cent copolymerized vinylidene cyanide.

5. A tripolymer of vinylidene cyanide, butadiene-1,3 and Z-methyl butadiene-1, 3, the vinylidene cyanide component being derived from monomeric vinylidene cya-v nide which is a crystalline solid at 0 C., having a meltingtpointwhen in purest form of substantially 9.0 to 9.7 C., and being characterized chemically by the ability to undergo on contact with water at room temperature an instantaneous homopolymerization reaction to give a solid water-insoluble resin, said interpolymer containing substantially 50 moleper cent copolymerized vinylidene cyanide.

6. A tripo'lymer of vinylidene cyanide, 'butadiene-l 3 and piperylene, the vinylidene cyanide component be-. ing derived from monomeric vinylidene cyanide whi h is a crystalline solid at 0 C.,'havinga melting point when in puresttformof substantially 9.0 to 9.7 C., and being characterized chemically by the ability to undergo on contact with Water: at room temperature an instantaneous homopolymerization reaction to give a solid water-insoluble resin, said interpolymer containing substantially 50 mole per cent copolymerized vinylidene cyanide,

7. The method which comprises dissolvingvinylidene cyanide which is a liquid at room temperature and a crystalline solid at.0 C., having a melting point when in purest form of-substantially 9.0 to 9.7 C., and is characterized chemically by the ability to undergo on contact with water at room temperature an instantaneous homopolymerization reaction to give a solid water-insoluble resin, and two conjugated aliphatic dienes in a liquid aromatic hydrocarbon and adding a polymerization catalyst whereupon polymerization occurs to form an interpolymer of vinylidene cyanide with said conjugated aliphatic dienes, said interpolymer. containing substantially 50 mole per cent copolymerized vinylidene cyanide.

8. The method which comprises dissolving vinylidene cyanide which is a liquid at room temperature and a crystalline solid at 0 C., having a melting point when in' purest: form of substantially 9.0 to 9.7 C., and is characterized chemically by the ability to undergo on contact with water at room temperature an instantaneous homopolymerization reaction to give a solid water-insoluble resin, butadiene-1,3, and another conjugated aliphatic-diene in a liquid aromatic hydrocarbon and adding a polymerization catalyst whereupon polymerization occurs to form an inter-polymer of vinylidene cyanide with said bntadiene-L3 and conjugated aliphatic diene, said interpolymer containing substantially 50 mole per cent copolymerized vinylidene cyanide.

9. The method .of claim 8 wherein the liquid aromatic hydrocarbon is benzene.

10. The method of claim 8 wherein the aliphatic diene is Z-methyl butadiene-l,3.

11. The method of claim 8 wherein the aliphatic diene is piperylene.

12. The method of claim 8 wherein the aliphatic diene is methyl pentadiene.

13. The method of claim 8 wherein the conjugated conjugated conjugated conjugated V aliphatic diene is 2,3-dimethyl butadiene-l,3. 

1. AN INTERPOLYMER COMPRISING VINYLIDENE CYANIDE COPOLYMERIZED WITH TWO CONJUGATED ALIPHATIC DIENES, THE VINYLIDENE CYANIDE COMPONENT BEING DERIVED FROM MONOMERIC VINYLIDENE CYANIDE WHICH IS A CRYSTALLINE SOLID AT 0* C., HAVING A MELTING POINT WHEN IN PUREST FORM OF SUBSTANTIALLY 9.0* C. TO 9.7* C., AND BEING CHARACTERIZED CHEMICALLY BY THE ABILITY TO UNDERGO ON CONTACT WITH WATER AT ROOM TEMPERATURE AN INSTANTANEOUS HOMOPOLYMERIZATION REACTION TO GIVE A SOLID WATER-INSOLUBLE RESIN, SAID INTERPOLYMER CONTAINING SUBSTANTIALLY 50 MOLE CENT COPOLYMERIZED VINYLIDENE CYANIDE. 